Rivals

“Persons dwelling on opposite sides of a river.” Forsyth
derives these words from the Latin rivalis, a riverman. Caelius
says there was no more fruitful source of contention than river-right,
both with beasts and men, not only for the benefit of its waters, but
also because rivers are natural boundaries. Hence Ariosto compares
Orlando and Agrican to “two hinds quarrelling for the river-right” (xxiii. 83).